A valve opening and closing limiting mechanism

Abstract

The utility model discloses a kind of opening and closing limiting mechanism of valve, it is related to valve technical field.The mechanism includes limit piece and gland, gland is connected with valve body by two fasteners, fastener protrudes from the surface of gland and is separately arranged on opposite sides of gland;First stop table and second stop table that respectively encircle corresponding fastener are protruded on the gland, both are in parentheses shape, including the arc connecting section of middle and linear section of both ends;Limit piece has first abutment and second abutment, when rotating to limit position with valve rod, abutment and the linear section side wall of corresponding stop table form surface contact and abut each other.By setting stop table around fastener, limit piece is abutted on stop table instead of directly contacting fastener, avoid that fastener bears transverse shear force;The arc connecting section of parentheses shape stop table enhances structural strength, linear section provides surface contact, contact area is big, wear-resistant, and limit precision is high;Two-point symmetrical limit makes stress balance, and structure is stable and reliable.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, and in particular to a valve opening and closing limiting mechanism. Background Technology

[0002] Valves are widely used in fluid transport pipelines, controlling the flow of the pipeline by rotating an opening and closing element driven by the valve stem. To ensure accurate positioning of the valve when fully open or closed, and to prevent damage to the sealing surface or operational failure due to excessive rotation, valves are typically equipped with an opening and closing limit mechanism. Existing opening and closing limit mechanisms generally include a fixed gland and a limit plate that rotates synchronously with the valve stem. The gland is fixed to the valve body by fasteners, which usually protrude from the surface of the gland. During valve opening and closing, when the limit plate rotates to its limit position with the valve stem, it abuts against the limiting structure on the gland, thereby achieving mechanical limiting.

[0003] In some existing valve structures, the limiting plate directly abuts against the fastener of the gland when in its extreme position, relying on the fastener to bear the impact force of the limiting plate. In this structure, the fastener is subjected to lateral shear force for a long time, which can easily lead to loosening or fatigue fracture, causing the connection between the gland and the valve body to fail, thereby affecting the sealing reliability and operational safety of the valve.

[0004] To address the aforementioned issues, some existing solutions employ a protective sleeve over the fastener, ensuring the limiting plate contacts the sleeve at its extreme positions, thus preventing direct impact between the limiting plate and the fastener. However, this approach only provides surface protection; the lateral shear force generated by the limiting plate impacting the protective sleeve is still transmitted to the fastener through the sleeve, leaving the fastener still subjected to shear loads. Over long-term use, this still carries the risk of loosening or breakage, failing to fundamentally solve the problem of fastener stress.

[0005] In addition, existing valve opening and closing limit mechanisms usually only have locking structures in the fully open and fully closed positions, which is relatively simple and cannot meet the operational requirements of locking the valve in the partially open state. Utility Model Content

[0006] The purpose of this invention is to address the problems of fasteners loosening or breaking due to lateral shear force and the lack of locking mechanisms for some opening positions. This invention provides a valve opening and closing limiting mechanism.

[0007] The technical solution of this utility model: The valve includes a valve stem and a valve body. The opening and closing limiting mechanism includes a limiting plate and a pressure plate. The pressure plate is used to connect to the valve body through fasteners, and the fasteners protrude from the surface of the pressure plate. The limiting plate is used to be fixedly sleeved on the valve stem so as to rotate synchronously with the valve stem. There are two fasteners, namely a first fastener and a second fastener, which are respectively provided on opposite sides of the pressure plate. A first stop and a second stop are protruding on the pressure plate. The first stop surrounds the first fastener, and the second stop surrounds the second fastener. Both the first stop and the second stop... It is shaped like a bracket, including a central arc-shaped connecting segment and straight segments connecting the two ends of the arc-shaped connecting segment; the limiting plate has a first abutment part and a second abutment part. When the valve stem rotates to the first limit position, the first abutment part contacts and abuts the side wall surface of the straight segment of the first stop plate, and the second abutment part contacts and abuts the side wall surface of the straight segment of the second stop plate; when the valve stem rotates to the second limit position, the first abutment part contacts and abuts the side wall surface of the other straight segment of the second stop plate, and the second abutment part contacts and abuts the side wall surface of the other straight segment of the first stop plate.

[0008] By employing the above technical solution, the first and second stop plates are respectively arranged around the corresponding fasteners, so that the limiting plate abuts against the stop plate rather than directly contacting the fastener at its extreme position. This avoids the fastener being subjected to lateral shear force, effectively preventing the fastener from loosening or breaking due to long-term shear impact, ensuring the reliability of the connection between the gland and the valve body, and thus ensuring the valve's sealing performance and operational safety. In the shape of the stop plate, the arc-shaped connecting section forms a continuous and smooth transition structure, enhancing the structural strength of the stop plate itself and avoiding stress concentration. The straight section's sidewall and the abutting part of the limiting plate form a smooth transition. With surface-to-surface contact, a large contact area, and low unit stress, it is not prone to wear or deformation under repeated opening and closing impacts, ensuring the limiting accuracy and long-term reliability. At the same time, the bracket-shaped stop plate surrounds the fastener to form a protective enclosure, further isolating the contact path between the limiting plate and the fastener, and improving the protection effect on the fastener. The first and second stop plates, together with the first and second abutting parts of the limiting plate, form a two-point surface contact abutting fit at both extreme positions of the valve stem, with symmetrical distribution of limiting force and balanced force, improving the stability and impact resistance of the limiting structure.

[0009] In one possible design, the first stop and the second stop are mirror-symmetrical.

[0010] The above design ensures that the limiting reaction force on the valve stem is symmetrical and balanced at the two extreme positions, avoiding eccentric loading and helping to maintain the coaxiality of the valve stem and the stability of long-term operation.

[0011] In one possible design, the limiting piece includes a central ring portion, a first abutting portion and a second abutting portion, which are respectively a first locking portion and a second locking portion extending radially outward from the central ring portion. The first locking portion and the second locking portion are located at the two ends of a radial straight line passing through the center of the central ring portion and are centrally symmetrical.

[0012] With the above design, the structure allows the two locking parts of the limiting plate to simultaneously form two-point contact with the corresponding stop plate during rotation. The limiting force is symmetrically transmitted to the valve stem along the diameter direction, reducing the risk of the valve stem bearing bending moment. The centrally symmetrical layout also makes the limiting plate itself subjected to balanced force and structural stability, and is easy to stamp or integrally molded.

[0013] In one possible design, the sidewalls of the first and second locking parts are flat, so as to form surface contact with the sidewall of the straight segment.

[0014] With the above design, the sidewalls of the first and second locking parts are flat, forming a plane-to-plane contact fit with the sidewall of the straight section of the stop. Compared with arc-shaped or line contact, plane-shaped contact further increases the effective contact area, significantly reducing the impact stress per unit area, effectively suppressing plastic deformation and wear of the contact surface during repeated opening and closing, extending the service life of the limiting plate and the stop, and improving the repeatability accuracy of the limiting position.

[0015] In one possible design, the gland also has an integrally formed first locking platform and second locking platform, which extend radially along the gland. The first locking platform has a first locking hole, and the second locking platform has a second locking hole. The center of the first locking hole and the center of the second locking hole are on a circle with the center of the valve stem as the center, and the central angle between them is 90 degrees. The first locking part has a first connecting hole. In the first extreme position, the first connecting hole and the first locking hole are coaxial. In the second extreme position, the first connecting hole and the second locking hole are coaxial. The opening and closing limiting mechanism also includes a locking member that can be inserted into the aligned first connecting hole and the first locking hole or the second locking hole to lock the limiting piece.

[0016] With the above design, the first locking hole and the second locking hole form a 90-degree angle with the center of the valve stem as the vertex, corresponding to the 90-degree opening and closing stroke of the valve from fully open to fully closed. The locking element can be inserted and locked at both the opening and closing extreme positions of the valve stem, so that the valve can be stably kept in the fully open or fully closed state, preventing the valve position from changing unexpectedly due to misoperation or external interference, and improving operational safety.

[0017] In one possible design, the gland is also integrally formed with a third locking platform, which extends along the radial direction of the gland and is located at the circumferential midpoint between the first and second locking platforms. The third locking platform has a third locking hole. When the valve stem is rotated to the half-open position, the first connecting hole and the third locking hole are coaxial, and the locking member can be inserted into the first connecting hole and the third locking hole to lock the limiting piece.

[0018] By adopting the above design, the structure realizes the position locking of the valve in the half-open state, which meets the requirement of keeping the valve opening fixed in the flow regulation operation, overcomes the functional limitation of the existing opening and closing limit mechanism that can only lock in the fully open and fully closed positions, and expands the application scenarios of the valve.

[0019] In one possible design, the gland is also integrally formed with at least one adjusting locking platform, which extends radially along the gland. The adjusting locking platform has an adjusting locking hole, the center of which and the center of the first locking hole are on a circle with the center of the valve stem as the center, and the central angle between them is between 90 degrees and 180 degrees. The second locking part has a second connecting hole, which can correspond to one of the adjusting locking platforms. At this time, the second connecting hole is coaxial with the adjusting locking hole of the adjusting locking platform, and the locking member can be inserted into the second connecting hole and the adjusting locking hole to lock the limiting piece.

[0020] By adopting the above design, at least one additional adjusting locking platform is added, providing an additional locking position within the range of 90 to 180 degrees, covering all opening and closing adjustment ranges of the valve stem. This allows the valve to be locked at multiple preset opening positions between fully open and fully closed strokes. This structure meets the locking requirements for various flow adjustment levels under different operating conditions, improving the valve's adaptability and operational flexibility in complex pipeline systems. Moreover, the locking holes are rationally distributed, avoiding positional conflicts with the first and second locking holes. In addition, the second locking part cooperates with the adjusting locking hole, effectively utilizing the locking part resources at both ends of the limiting plate, allowing the locking parts at both ends to undertake locking functions within different angle ranges, resulting in high structural utilization.

[0021] In one possible design, the arc-shaped connecting segment is arc-shaped and conforms to the outer contour shape of the corresponding surrounding fastener.

[0022] With the above design, the arc-shaped connecting section is arc-shaped and matches the outer contour shape of the corresponding surrounding fastener, so that the stop and the fastener maintain a uniform surrounding gap, resulting in a compact structure and neat appearance. At the same time, the arc-shaped connecting section can evenly distribute part of the load along the arc path to the pressure plate substrate when the limiting plate impacts the straight section, similar to the principle of an arch, further improving the overall impact resistance of the stop. Attached Figure Description

[0023] Figure 1This is a schematic diagram of the external structure of this utility model;

[0024] Figure 2 This is a partial structural schematic diagram of the present invention;

[0025] Figure 3 This is a top view of the main structural components of this utility model;

[0026] Figure 4 This is a partial structural diagram of the valve stem of this utility model when rotated to the half-open position;

[0027] Among them, 1. Valve body;

[0028] 2. Valve stem;

[0029] 3. Pressure cap; 31. First stop platform; 311. Arc-shaped connecting section; 312. Straight section; 32. Second stop platform; 33. First locking platform; 331. First locking hole; 34. Second locking platform; 341. Second locking hole; 35. Third locking platform; 351. Third locking hole; 36. Adjusting locking platform; 361. Adjusting locking hole;

[0030] 41. First fastener; 42. Second fastener;

[0031] 5. Limiting piece; 51. Central ring; 52. First locking part; 521. First connecting hole; 53. Second locking part; 531. Second connecting hole. Detailed Implementation

[0032] like Figures 1 to 4 The diagram illustrates an opening and closing limiting mechanism for a valve. The valve includes a valve stem 2 and a valve body 1. The limiting mechanism includes a limiting plate 5 and a pressure cap 3. The pressure cap 3 is fixedly connected to the valve body 1 by fasteners, the heads or nuts of which protrude from the surface of the pressure cap 3. The limiting plate 5 is fixedly sleeved on the valve stem 2 and can rotate synchronously with the valve stem 2. In this embodiment, there are two fasteners, namely a first fastener 41 and a second fastener 42, which are respectively located on opposite sides of the pressure cap 3. The fasteners are specifically bolts, with the heads or nuts of which protrude from the surface of the pressure cap 3. Packing material can be further provided between the pressure cap 3 and the valve body 1, and the pressure cap 3 achieves a circumferential seal on the valve stem 2 by compressing the packing material.

[0033] The pressure cap 3 has a first stop 31 and a second stop 32 protruding from it. The first stop 31 surrounds the first fastener 41, and the second stop 32 surrounds the second fastener 42. Both stops are bracket-shaped or arch-shaped. Specifically, each stop includes a central arc-shaped connecting section 311 and straight sections 312 connecting the two ends of the arc-shaped connecting section 311. The arc-shaped connecting section 311 is preferably circular and matches the outer contour shape of the corresponding surrounding fastener, so that a uniform surrounding gap is maintained between the stop and the fastener. The first stop 31 and the second stop 32 are mirror-symmetrical.

[0034] The limiting piece 5 includes a central ring portion 51, and a first locking portion 52 and a second locking portion 53 extending radially outward from the central ring portion 51. The first locking portion 52 and the second locking portion 53 are located at the two ends of a radial straight line passing through the center of the central ring portion 51 and are centrally symmetrical. The first locking portion 52 and the second locking portion 53 respectively constitute the first abutting portion and the second abutting portion of the limiting piece 5. The sidewalls of the first locking portion 52 and the second locking portion 53 are flat so as to form a surface contact fit with the sidewall of the straight section 312 of the stop platform.

[0035] When the valve stem 2 rotates, the limiting piece 5 rotates synchronously with the valve stem 2. When the valve stem 2 rotates to the first limit position (e.g., the valve is fully open), the first locking part 52 forms a surface contact with the side wall of the straight segment 312 of the first stop 31, and at the same time, the second locking part 53 forms a surface contact with the side wall of the straight segment 312 of the second stop 32. At this time, the limiting piece 5 does not contact the first fastener 41 and the second fastener 42, and the fastener is not subjected to lateral shear force. When the valve stem 2 rotates to the second limit position (e.g., the valve is fully closed), the first locking part 52 forms a surface contact with the side wall of the other straight segment 312 of the second stop 32, and at the same time, the second locking part 53 forms a surface contact with the side wall of the other straight segment 312 of the first stop 31. Similarly, the limiting piece 5 does not contact the fastener at this position, and the connection state of the fastener is not affected by limiting impact.

[0036] Since the sidewalls of the first locking part 52 and the second locking part 53 are flat, and the sidewall of the straight section 312 of the stop platform is also flat, they form a surface-to-surface contact fit when they come into contact. This surface-to-surface contact method increases the effective contact area, significantly reduces the impact stress per unit area, effectively suppresses wear and plastic deformation of the contact surface during repeated opening and closing, and improves the long-term retention capability of the limiting accuracy.

[0037] The arc-shaped connecting section 311 of the stop platform forms a continuous and smooth transition structure, with one end connecting to the straight section 312 and the other end connecting to the base of the pressure cap 3 or the straight section 312 at the other end. This arc-shaped connecting section 311 enhances the overall structural strength of the stop platform, avoids stress concentration at the root, and evenly distributes part of the load transmitted by the impact of the limiting piece 5 on the straight section 312 along the arc-shaped path to the base of the pressure cap 3, further improving the impact resistance of the stop platform.

[0038] The stop plate surrounds the fastener, forming a protective enclosure around it. This spatially isolates the contact path between the limiting plate 5 and the fastener, structurally ensuring that the limiting plate 5 will not collide or be squeezed with the fastener at any rotation angle, thus solving the problem of the fastener bearing lateral shear force.

[0039] The pressure cap 3 is integrally formed with a first locking platform 33, a second locking platform 34, and a third locking platform 35 along its radial direction. The first locking platform 33 has a first locking hole 331, and the second locking platform 34 has a second locking hole 341. With the center of the valve stem 2 as the apex, the angle between the line connecting the center of the first locking hole 331 and the center of the valve stem 2, and the angle between the line connecting the center of the second locking hole 341 and the center of the valve stem 2, is 90 degrees. This 90-degree angle corresponds to the standard opening and closing stroke of the valve from fully open to fully closed. The first locking part 52 has a first connecting hole 521. When the valve stem 2 rotates to the first limit position, the first connecting hole 521 and the first locking hole 331 are coaxially aligned; when the valve stem 2 rotates to the second limit position, the first connecting hole 521 and the second locking hole 341 are coaxially aligned. This opening and closing limiting mechanism also includes a locking element, which can be, for example, a locking pin or a padlock's locking beam. The operator can insert the locking element into the aligned first connecting hole 521 and the first locking hole 331 or the second locking hole 341 to lock the limit piece 5 in the current limit position, so that the valve is stably kept in the fully open or fully closed state, preventing accidental changes in the valve position due to misoperation or external interference.

[0040] The third locking platform 35 is located circumferentially between the first locking platform 33 and the second locking platform 34, and a third locking hole 351 is provided on the third locking platform 35. When the valve stem 2 rotates to the half-open position, the first connecting hole 521 and the third locking hole 351 are coaxially aligned, and the operator can insert the locking element into it to lock the limiting piece 5, thereby locking the valve in the half-open state. This function meets the requirement of maintaining a fixed valve opening in flow regulation conditions and overcomes the limitation of conventional opening and closing limiting mechanisms that can only lock in the fully open and fully closed positions.

[0041] The first locking platform 33, the second locking platform 34, and the third locking platform 35 all extend along the radial direction of the pressure cover 3 and are integrally formed with the pressure cover 3. They have high connection strength and shear resistance, and can reliably withstand the torque transmitted by the limiting piece 5, ensuring a firm and reliable lock.

[0042] The pressure cap 3 also has at least one adjusting locking platform 36 integrally formed on it. The adjusting locking platform 36 extends radially along the pressure cap 3 and has an adjusting locking hole 361. With the center of the valve stem 2 as the vertex, the included angle between the line connecting the center of the adjusting locking hole 361 and the center of the valve stem 2 and the line connecting the center of the first locking hole 331 and the center of the valve stem 2 is between 90 degrees and 180 degrees. For example, if two adjusting locking platforms 36 are provided, the included angles formed are 120 degrees and 150 degrees respectively. The second locking part 53 has a second connecting hole 531. The second locking part 53 can correspond to one of the adjusting locking platforms 36. When the second connecting hole 531 is coaxially aligned with the adjusting locking hole 361 of the adjusting locking platform 36, the locking member can be inserted into the two to lock the limiting piece 5. Since the central angle between the adjusting lock hole 361 and the first lock hole 331 is between 90 degrees and 180 degrees, this locking position covers multiple preset opening degrees within the range of 90 degrees to 180 degrees of rotation of the valve stem 2 from fully open to fully closed, thus meeting the locking requirements of various flow adjustment levels under different working conditions.

[0043] Through the combined layout of the first locking platform 33, the second locking platform 34, the third locking platform 35 and at least one adjusting locking platform 36, the opening and closing limiting mechanism of this embodiment can reliably lock at multiple positions during the opening and closing stroke of the valve stem 2. It is feature-rich, highly adaptable, and significantly improves the operational flexibility of the valve in complex pipeline systems.

[0044] It should be noted that in the above embodiments, the first limit position can be the valve's open position and the second limit position can be the valve's closed position; alternatively, the first limit position can be the valve's closed position and the second limit position can be the valve's open position. Both correspondences are acceptable, and this opening and closing limit mechanism can adapt to different valve operating habits and pipeline installation directions, exhibiting strong versatility.

Claims

1. A valve opening and closing limiting mechanism, the valve comprising a valve stem (2) and a valve body (1), the opening and closing limiting mechanism comprising a limiting plate (5) and a pressure cap (3), the pressure cap (3) being connected to the valve body (1) by fasteners, the fasteners protruding from the surface of the pressure cap (3), the limiting plate (5) being fixedly sleeved on the valve stem (2) to rotate synchronously with the valve stem (2); characterized in that: The number of fasteners is two, namely the first fastener (41) and the second fastener (42), which are respectively located on opposite sides of the pressure cap (3); The pressure cap (3) is provided with a first stop (31) and a second stop (32). The first stop (31) is arranged around the first fastener (41), and the second stop (32) is arranged around the second fastener (42). Both the first stop (31) and the second stop (32) are in the shape of a bracket, and both include an arc-shaped connecting section (311) in the middle and a straight section (312) connecting the two ends of the arc-shaped connecting section (311). The limiting piece (5) has a first abutting part and a second abutting part. When the valve stem (2) rotates to the first limit position, the first abutting part contacts and abuts the side wall of a straight line segment (312) of the first stop platform (31), and the second abutting part contacts and abuts the side wall of a straight line segment (312) of the second stop platform (32). When the valve stem (2) rotates to the second limit position, the first abutting part contacts and abuts the side wall of another straight line segment (312) of the second stop platform (32), and the second abutting part contacts and abuts the side wall of another straight line segment (312) of the first stop platform (31).

2. The valve opening and closing limiting mechanism according to claim 1, characterized in that: The first stop (31) and the second stop (32) are mirror images of each other.

3. The valve opening and closing limiting mechanism according to claim 1, characterized in that: The limiting piece (5) includes a central ring portion (51), the first abutting portion and the second abutting portion are respectively a first locking portion (52) and a second locking portion (53) extending radially outward from the central ring portion (51). The first locking portion (52) and the second locking portion (53) are located at the two ends of a radial straight line passing through the center of the central ring portion (51) and are centrally symmetrical.

4. The valve opening and closing limiting mechanism according to claim 3, characterized in that: The sidewalls of the first locking part (52) and the second locking part (53) are flat, so as to form a surface contact with the sidewall of the straight segment (312).

5. The valve opening and closing limiting mechanism according to claim 3, characterized in that: The pressure cap (3) is also integrally formed with a first locking platform (33) and a second locking platform (34). The first locking platform (33) and the second locking platform (34) extend along the radial direction of the pressure cap (3). The first locking platform (33) has a first locking hole (331), and the second locking platform (34) has a second locking hole (341). The center of the first locking hole (331) and the center of the second locking hole (341) are on a circle with the center of the valve stem (2) as the center, and the central angle between them is 90 degrees. A first connecting hole (521) is provided on a locking part (52). In the first extreme position, the first connecting hole (521) is coaxial with the first locking hole (331). In the second extreme position, the first connecting hole (521) is coaxial with the second locking hole (341). The opening and closing limiting mechanism also includes a locking member. The locking member can be inserted into the aligned first connecting hole (521) and the first locking hole (331) or the second locking hole (341) to lock the limiting piece (5).

6. The valve opening and closing limiting mechanism according to claim 5, characterized in that: The pressure cap (3) is also integrally formed with a third locking platform (35). The third locking platform (35) extends along the radial direction of the pressure cap (3) and is located at the circumferential middle position between the first locking platform (33) and the second locking platform (34). A third locking hole (351) is provided on the third locking platform (35). When the valve stem (2) is rotated to the half-open position, the first connecting hole (521) and the third locking hole (351) are coaxial. The locking member can be inserted into the first connecting hole (521) and the third locking hole (351) to lock the limiting piece (5).

7. The valve opening and closing limiting mechanism according to claim 5, characterized in that: The pressure cap (3) is also integrally formed with at least one adjusting locking platform (36), which extends along the radial direction of the pressure cap (3). The adjusting locking platform (36) is provided with an adjusting locking hole (361). The center of the adjusting locking hole (361) and the center of the first locking hole (331) are on a circle with the center of the valve stem (2) as the center, and the central angle between them is between 90 degrees and 180 degrees. The second locking part (53) is provided with a second connecting hole (531). The second locking part (53) can correspond to one of the adjusting locking platforms (36), and at this time the second connecting hole (531) is coaxial with the adjusting locking hole (361) of the adjusting locking platform (36). The locking member can be inserted into the second connecting hole (531) and the adjusting locking hole (361) to lock the limiting piece (5).

8. The valve opening and closing limiting mechanism according to any one of claims 1 to 7, characterized in that: The arc-shaped connecting section (311) is arc-shaped and is adapted to the outer contour shape of the corresponding surrounding fastener.

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